Lab member Klaus Nielsen, along with the Andersen Lab at Aarhus University in Denmark, detail how structural changes in the ratchet domain of the DEAH-box ATPase Prp43 could allow translocation. Using genetics, biochemistry, and structural data, Klaus and colleagues show that two hairpins, as well as a dynamic motif, are implicated in allowing 3' to 5' movement along RNA. Interestingly, these data also reveal similarities between Prp43 and viral helicases.